Miter boxes are cutting guides that allow precision cuts using hand-held saws, because they both constrain the saw to move in a straight line and also align the cutting path with respect to the object being cut. Typical miter boxes are designed for hand-operated saws, and include cutting guides for 90-degree cross cuts, as well as 45-degree miter cuts. The cutting guides in a typical miter box are usually pairs of notches on opposing sides of the box, barely wider than the saw blade, and which are oriented at a precise angle with respect to the box's inner surfaces. These surfaces are a cutting surface, which the blade will score as it cuts through the object, and at least one other alignment surface, which may be identified as a fence. A miter box typically forms a 3-sided trough with a cutting surface at the bottom, and two fences protruding above the cutting surface. The notches are in the fences.
An object to be cut is placed on the cutting surface and held firmly against a fence. The saw blade is then placed in a set of notches, and the user may cut the object by sliding the saw blade back and forth within the notches. The notches work well for guiding hand-operated saws, because the blade spans the width of the miter box and is held in place by both notches. Further, the cutting edge of the blade only engages the object to be cut and the cutting surface. That is, the cutting edge of the blade does not contact the fences.
A typical miter box will not work with a common hand-held power saw, because the blade will not be held in place by both notches simultaneously when the cutting starts. Further, because the blade is circular, it will strike the distant fence and likely cut a new notch in it. For example, if an object to be cut is placed in a typical miter box, the power saw blade is set in one the notch of the first fence, and the saw is turned on, the single notch is unlikely to properly constrain the blade. As a result, as the user passes the saw through the object toward the second fence, the blade will likely engage the fence somewhere other than the pre-cut notch in the second fence. The cutting edge of the blade will then just cut a new notch in the second fence. The miter box will become damaged, and will not have achieved its purpose.
A common power tool for making precision cuts is a power miter saw. A power miter saw arrangement provides a cutting surface, typically a single fence, and a power saw attached to a precisely-oriented moving arm. The arm is allowed to move in an arc about a pivot point, and the angle of the arm motion is usually adjustable. A power miter saw allows precise cuts by guiding the blade via a calibrated arm attached to the motor and coupled to the fence.
Unfortunately, power miter saws may be expensive and heavy, and are often unsuited for some of the tasks for which a power saw is commonly used. Thus, a user may have two saws: a power saw for general cutting tasks and power miter saw for precision cuts. This duplication of power saws can be expensive and burdensome to transport to a job site.